Telephone-exchange system



I Jan. 8 1924. 1,480,240

I E. H. CLARK TELEPHONE EXCHANGE SYSTEM Filed April 22 .1920 4 Sheets-Sheet 1 Ill/Ill i Y b 3 M-hn y Jan. 8 1924. 1,480,240 E. H. CLARK TELEPHONE EXCHANGE SYSTEM Filed April 22. .1920 4Sheets-Shet 2 lumm a l wig vi 5 E Q I E L f i I Jan. 8, 1924. 1,480,240

' E. H. CLARK TELEPHQNE EXCHANGE SYSTEM F 1920 4 Sheets-$heet 5 1 LJ. w 1: 1

Jan. 8 1924.

E. H. CLARK TELEPHONE EXCHANGE SYSTEM Filed April 22 1920 4 Sheets-Sheet 4 ge @x P F N F m wnv EQnX Patented Jan. 8, 1924.

-ws mres Parser I EDGAR H. CLARK, OF RICHMOND'HILL, NEW YORK, ASSIGNOR TO WESTERN ELECIRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y.;, A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE Application filed April2 2, 193g. Serial K653753104.

which the following is a full, clear, concise,

and exact description.

This invention relates to telephone ex? change systems employing automatic switching apparatus for establishing talking C011 nections between subscribers lines. More particularly, the invention relates to a system involving a plurality of oflices and in which facilities are provided for the establishment of talking connections between subscribers lines belonging to an office equipped with switches of the power driven type, that is, switches arranged to be driven from a continuously operating source of kinetlc en" ergy, and subscribers lines belonging to an oflice equipped with switches of the step-bystep type.

An object of the invention is the provision, in a system of the foregoing character,

of means whereby a subscribers line, terminating in an office provided with switches of the power-driven type, may be extended to mother subscribers lines in the same ofiice or to subscribers lines in another ofiice equipped with power-driven switches or to a distant office equipped with switches of the step-by-step type, together with means at the originating office for controlling the selective operation of switches of either type,

A feature of this invention is the provision of a class register for altering the circuits of the sending equipment of the type.

employed for controlling powerdriven switches, comprising a fundamental circuit, counting relays, and registers, in such man ner that when the desired line terminates in the originating office, or in an office having switching mechanism ofthe power-driven type, the sending equipment will function in the usual manner to control such powerdriven switches, but when the desired line terminates in an oflice having switching mechanism of the step-by-step type, the

sending equipment will function in a different manner to control such switches.

A further feature of the invention is the,

provision of an interrupting device associated with the circuits of the sendingequipment for opening and closi ng thetfugnda; mental cireuit to ,cause the stepping of step; by-step switches in accordance with theset ting of the registers of the sendingrequip ment.

Such other further features as, are con;

templated by the present invention, will be; come apparent from the following; descrip tion and the iap'pended- -c'laims, 4 v

e w r e en rren e ith F gure 2 at the right of Figu-re 1, Figure?) be, low Figure l, and igure tattheright of Figure 3, with Ethehlines" which are'draw n to theedges of the respe ctive sheetsin walign-,. ment, show so much of a completetelephone,

exchange as is necessary to; disclose th-is invention. Figure 1 represents aflcalling sub: scribers line and an operators position pro;

vided with a link circuit terminatingin an answering plug andin an oflice. selector switch. Figure :2 represents.diagrammati cally two oflices of theexchange to which the officeuselector {Of Figure 1 has access, one ofl ice Xbeing represented :in the upper por.- tion of the figure as having mechanical sw tching equipment of the power-driven panel type, and the other oflice Y represen ed in the lowerportionofthefigure as hav- 1ng switching equipment of the step-by-step type, and called subscribers lines terminate ing in each of the office st, Figure -3,rep;re-"

sents the operatorssendingequipment; i'gw ure 4 represents a portionionly of the ,keys

of the operators key-board andfthe registers upon which the operator sets up ,the num- :bers of the, desired lines for oontrolling the setting of the selector switches Inthe system embodying this inventi'on, the number of the line desired by the calling subscriberis set upon a setof registering mechanisms at the originating office, the first digit of the number determiningthe particular office of the exchange in which the desired line terminates. which takes a setting in acordance with the first or office digit of the number isprovided with extra contacts which serve as a class switch to alter the sending and control circuits of the operators sendin equipment inv vaccordance with the nature of the :oflice to,

which thecalling line is to be connected by The office register vertive impulses sent back to the operators sender through the selective movements of the switches, the class switch contacts of the office register permit the sender circuits to function in the well-known and usual manner. 0n calls into oflices provided with selector switches of the step-by-step type, which are selectively controlled at the sender by impulses transmitted thereto by the selective opening and closing of the fundamental circuit leading thereto, the class switch contacts of the oflice register cause the operation of a stepping relay at the sender under the control of the interrupter to selectively open and close the fundamental circuit in accordance with the setting of the number registers. The sets of impulses corresponding to the several digits. of the line designation are properly spaced to permit the trunk hunting movements of the selector switches by means of a slow-to-energize relay which controls the advance of the sender sequence switch.

The ofice selector shown in Figure 1 is of the type shown and disclosed in Patent No. 1,123,696 issued January 5, 1915 to Craft and Reynolds. To simplify the circuits of the ofiice selector and of the operators sender, the office selector is shown as provided with a single set of shaft wipers and is therefore adapted to be set by a single set of directive impulses controlled by the ofice register. The incoming selector and final selector of the office represented in the upper portion of Figure 2 at K have, in order to simplify the circuits, been diagrammatically represented by a set of shaft wipers of each switch. These switches are of the panel type shown in the patent to Craft and Reynolds above referred to and function in the wellknown manner..

The office represented in the lower por tion of Figure 2 by character Y is provided with step-by-step switches of the type disclosed in Patent No. 1,231,013 issued June 26, 1917 to C. L. Goodrum. A part only of the circuits of the first selector switch have been disclosed, the second selector and connector switch being represented by the wipers of such switches.

In Figures 1 and 3 sequence switches 100 and 300 respectively have been shown. These switches are of substantially the same type as disclosed in Patent No. 1,127,808, issued February 9, 1915 to Reynolds and Baldwin. Each switch is provided with a motor magnet, which, when energized, forces a rotatably mounted disc into contact with a constantly rotating disc and thereby rotates a spindle on which are mounted a number of contact operating cams. Cams 102 to 111 of sequence switch 100, and cams 302 to 313, 311 to 313 of sequence switch 300 are arranged to close circuits only in the positions indicated by the numerals adjacent thereto. Cams 101 and 301 are so arranged ing closes a contact which is grounded through one of the operators digit keys, when the circuit of the registermagnet is opened. Each register therefore assumes a position corresponding to the position of the digit key in the bank which the operator has depressed. I

The organization and operation of the system disclosed may best be understood by a detailed description of the establishment of a connection, first from the line of subscriber A to the line of subscriber B in the ofiice X by means of switching mechanism of the power-driven type, and secondly from the line of subscriber A to the line of subscriber C in the ofhce Y, over switching mechanism of both the. power-driven type and of the step-by-step type.

Connection with an ofitee equipped with power-driven switches.

It will first be assumed that subscriber A desires a connect-ion with subscriber B, whose line designation is 96975, and removes his receiver from the switchhook to initiate the call. Upon the removal of the receiver from the switchhook, a circuit is 10 and the right-hand winding of line relay 18 to ground. The energization of line relay 1S closes a circuit for the line lamp 19 in an obvious manner. The operator whose set is designated by 0, upon observing the lighting of line lamp 19, inserts the plug P of one of her cord circuits into the jack J which is associated with the lighted line lamp 19. This results in the establishment of a circuit extending from grounded battery through the winding of cut-off relay 10, over the sleeve contacts of jack J and plug P, and thence to ground through the winding of relay 112. The energization of cut-off relay 10 removes the line relay 18 and its associated line lamp from the control of the subscribers line. The energization of relay 112 completes a circuit extending from grounded battery through the magnet winding of sequence switch 100, the upper lefthand contact of sequence switch earn 102 (1) and to ground through the front contact and armature of relay 112. The sequence switch 100 is thereby driven into position 2 under the control of its contact 101.

When the sequence switch 100moves into position 2, a circuit is established for relay 314 associated with the operators sending circuits, which circuit may be traced from grounded battery through the winding of relay 314, the upper right-hand contact of sequence switch cam 302 (1) to conductor 113, and thence to ground through the lower contact of sequence switch cam 103 (2). Relay 314 upon energizing closes a locking circuit for itself extending through its winding, the lower contact of sequence switch cam 302 (1 to 16), the right-hand armature and front contact of relay 314 and thence over conductor 114 to ground at the upper contact of sequence switch cam 103 (2 to 11). At itslefthand armature and front contact, relay 314 closes a circuit for driving the sender sequence switch 300 out of position 1 and into position 2, this circuit extending from grounded battery through the magnet winding of sequence switch 300, the upper right-hand contact of sequence switch cam 303 (1), and thence to ground at the front contact and left-hand armature of relay 314.

The operator, upon extending the connection to the calling subscribers line, depresses her listening key K, thereby connecting her set 0 with the subscribers line and receives instructions from the calling subscriber for the further extension of the connection. In accordance with the instructions received, the operator depresses keys of her key-board corresponding to the number of the line desired. Under the assumption that the calling subscriber desires connection with line B located in an ofiEice having power-driven switches, the number of such line being 9697 5, the operator depresses office key K, thousands key K hundreds key K tens key K and units key K Upon the depression of units key K a circuit is established for starting the register switches, 410, 420, 430, 440 and 450, which circuit extends through the windings of the magnets of these registers in parallel and thence over conductor 470 to ground at the right-hand contact of units key K Each of these registers will thereupon move from the position in which it has now been found to a position determined by the keys K to K respectively. In the case of register switch 410, the movement will continue until the ninth position is reached, in which a circuit is established from the grounded contact at key K register switch contact 411 (9), the winding of relay 471, and thence to grounded battery. Relay 471 attracts its armatures, thereby opening at its righthand armature contacts the energizing circuit of the motor magnet of register switch 410. At the same time, a circuit is established from grounded battery through the winding of relay 47 7 over the common conductor 478, the front contact and left-hand armature of relay 471, common conductor 47 9, and thence by one path through the winding of relay 480, to U second path through the left-hand armatures and back "contacts of relays 472 and 475 to ground. It will be noted that relay 47 7 will energize in this circuit, butthat relay 480 will be short-circuited untileach of the 1eft-handarmatures of relays 471 to 475 inclusive have been attracted.

The setting of the thousands register, the hundreds register, the tens register and the units register is similar tothat described in connection with the setting of the oiiice register and these settings take place simultaneously. When all are completed, the registers will be in the following positions: the oifice register in position 9; the thousands register in position 6; the hundreds register in position 9; the tens register in position 7 and the units register in position 5.

At this time the shunt around the winding of relay 480 will be removed and current flowing therethrough will cause its energization. A circuit is thereby established extending from grounded battery through the magnet winding of sequence switch 300, the upper contact of sequence switch spring 304 (2), and thence to ground through the armature and front contact of relay 480.

Sequence switch 300 thereupon moves under the control of its contact 301, out of position 2 and into position 3.

"When sequence switch 300 reaches position 3, a circuit is established from ground at sequence switch earn 305, extending over the common conductor 481 and thence in parallel through the windings of the release magnets 482 to 486 inclusive to grounded battery. The energization of these release magnets causes the release of the keys K to lit inclusive, thereby deenergizing relays 471 to 475 inclusive. Each of these relays retracts its armatures and in so doing causes the deenergization of relays 477 and 480.

Relay 477 in retracting its armature establishes a circuit extending from grounded battery throughthe magnet winding of sequence switch 300, the lower contact of sequence switch cam 304 (3) and thence to ground at the armature and back contact of relay 477. Sequence switch-300 under the control of its contact 301 moves into its fourth position. In this position a circuit, known as the fundamental circuit, is established which extends from grounded battery through the winding of relay 115 at ound, and by a the ofiice selector switch 116, the lower righthand contact of sequence switch cam 104, conductor 117, the right-hand armature and back contactof stepping relay 315, the righthand armature and back contact of counting relay '0, the winding of stepping relay 316, the upper left-hand contact of sequence switch cam 306 (4:), conductor 118, and thence to ground through the lower lefthand contact of sequence switch cam 105 (2 and 3).

Relay 115 energizes in this circuit, closing through its left-hand armature and front contact a locking circuit for itself, extend ing through the lowerleft-hand contact of sequence switch cam 104, (2 and 3), and thence over the fundamental cir'cuitIpreviously traced. This circuit maintains relay 115 energized after the sequence switch-is driven out or" position 2, a circuit for advancing sequence switch 100 now extending from grounded battery through'the magnet winding of sequence switch 100, the lower right-hand contact of sequence switch cam 106 (2), and thence to ground at'the righthand armature and front contact of relay 115.

In position 3 of sequence switch '100, a circuit is established extending from grounded battery through the winding ofthe updrivemagnet 119, the'lower left-hand contact of sequence switch cam 107 (3), and thence to ground at the right-hand armature and front contact of relay 115. Magnet 119 attracts its armature and in so doing presses the depending portion 120 of the switch shaft against the constantly rotating roller 121, whereby the brush carriage 122 is elevated. As the brush 123 passes over the conducting segments of commutator'124, the stepping relay 316 is intermittently dcenergized and energized.

Upon the initial energization of stepping relay 316, a circuit is established extending from ground at the armature of relay 316 through the upper left-hand contact of sequence switch cam (4:), the upper righthand contact of the office register cam 4:12 (9), conductor 353, to the armature and back contact of counting relay 9, the winding of counting relay 9 to grounded battery.

Relay 9 is'thereupon energized and completes a locking circuit for itself extending from grounded battery through its winding, the winding of relay 9,-the armature and front contact of relay 9, and thence to groundat the upper right-hand contact of sequence switch cam 308 Counting relay 9, however, is shunted at this time through the conductor .353 over'the circuit previously traced and does not energize until the stepping relay 316 retracts its armature.

When the brush 123 passes over the first conducting segment of commutator 124, re-

inseam lay 316, throughthe shunt thus established, becomesfdeenergized and thereupon retracts its armature, This results in the-energization of counting relay 9 whichthereupon transfers the groundconnected to conductor 353'to' the armature and'back contact-of counting relay 8 to the winding of relay 8, and thence to grounded battery. Relay 8 is now energized over the'cir'c'uit leading from groundatthe armature contact of stepping relay 316, sequence switch cam 307 (4), as previously "traced through conductor 353, the armature and'front contact of relay 9, the armature andco'ntact of counting relay 8,'the winding or counting relay 8, and thence to grounded battery. in a similar manner each one or the upper counting re lays 8 to 0 is, energized by the passing of brushf1'23ove'r the segments of commuta tor 1'24 and the consequent deenergization of stepping relay 316. When counting relay Ois energized by attracting its right-hand armature, it opens the fundamental circuit, thereby causing the-deenergization of reay l The energization of counting relay 0 also results in the establishment of a circuit extending from grounded battery through the winding of sequence switch 300, the lower right-hand contact of oii'ice register cain 413 (9), conductor 322, the frontcontact and left-hand armature of relay 0' andthence to ground at the upper left-hand contact of sequence switch earn 308 Sequence switch 300 under the controlof its contact 301 moves its cams into the sixth position, whereupon the lockingcircuit of the energized counting relays is broken at the upper right-hand contact of sequence switch cam 308 (4). I

The deenergization of relay 115 results in" the opening'oi the circuit through the up-drive magnet 119 for arresting the upward movement or the switch shaft, and in the establishment of a circuit for driving sequence switch 100 out otpo, 'tion 3 and into position 6. This circuit may be traced from: grounded battery through the magnet winding of sequence switch 100, the-lower left-hand contact of sequence switch cairn and thence to ground the back contact and right-hand armature oi: relay 115.

Since, as has been assumed, the O'E llCB selector has only one selective movement, its wipers may now be driven over the se lected group of contacts in their hunting movement to select an idle trunk from the group leading to the desired ofiice. To accomplish this hunting movement a circuit is established for the test relay 125,which may be traced from grounded battery through the right-hand winding of this relay and thence to ground at the lower contact oi? sequence switch cam'108 (in) 6). Relay 125,

' upon energizing, closes a locking circuit for itself extending from grounded battery through its l ft-hand winding, its inner lefthand armature and front contact and thence to the test wiper 126. If the wipers are now resting upon the terminals of a busy trunk, there will be ground potential upon the test terminal of the trunk: and test relay 125 will therefore remain locked after its initial energizing circuit is opened at sequence switch cam 108 when sequence switch 100 leaves position 6 which it does imme diately upon the energization of relay 125. The circuit for driving sequence switch 10.0 out of position 6 and into position 7 may be traced from grounded battery through the magnet winding of sequence switch 100, the lower right-hand contact of sequence switch cam 109 (6), and thence to ground through the front contact and right-hand armature of relay 125. With sequence switch 100 in position 7, and relay 125 locked up, a circuit is now established for the up-drive magnet 119 for driving the brush carriage upwardly in search of an idle trunlr in the selected group of trunks.

This circuit maybe traced from grounded battery through the winding of the updrive magnet 119, the lower right-hand contact of sequence switch cam 107 (7) and thence to ground at the right-hand armature and. front contact of relay 125. As soon as an idle trunlr is found; the locking circuit through the left-hand winding of relay 125 is opened and this relay deenergizes as soon as the brush set has been centrally positioned upon the terminals of the selected idle trunk, when a locking circuit eX- tending through the right-hand winding of relay 125, through the upper contact of sequence switch cam 108 (7), the outer lefthand armature and front contact of relay 125, over conductor 127 to ground at commutator segment 128 and brush 129, is opened;

Relay 125 upon deenergizing opens the circuit'of up-drive magnet and at its righthand armature and back contact closes a circuit extending through the lower left hand. contact 01' sequence switch cam 109 (7 and through the winding of sequence switch 100 for driving the sequence switch out of position 7 and into position 11 In position 11, conductors 117 and 118 of the fundamental circuit are extended through the lower contacts of sequence switch cams 110 and 111 respectively, to the talking conductors of the link circuit and thence over the wipers of the oflice selector to the conductors of the selected inter-ofhce trunk. The stepping relay 316 of the ofiice sender is now energized over the fundamental circuit'in series with the control relay (not shown) of the incoming selector 200 in the selected oflice X. In view of the fact that back-contact of relay 315, the right-hand armature and back contact of counting re- 7 lay 0, the winding of stepping relay 316, the lower right-hand contact of sequence switch cam 306 (6), conductor 317 the lower right-hand contact of office register cam 414 (9), conductor 318, and thence to conductor 118.

Stepping relay 316 upon energizing closes a circuit extending from ground at its armae ture contacts through the lower contact of sequence switch cam 309 (6), right-hand contact of the thousands register cam 421 (6), conductor 354, the armature and back contact of counting relay 3, the'winding of counting relay 3, and thence to grounded battery. The method of translation for changing the registration set up in accord. ance with the decimal system of notation upon the sender registers for controlling panel type switches which operate upon a non-decimal selective basis, being well known in the art, is not described, in detail herein. For such detailed description, reference may be had to Patent No. 1,345,016, issued June 29, 1920 to A. E. Lundell and F. A. Stearn. The energiz'ation of counting relay 3 causes the establishment of a locking circuit extending through the winding of relay 3, the winding of relay 3, the armature and front contact of relay 3,"*and thence to ground atthe upper right-hand contact of sequence switch cam 308 (6 to Relay 3 does not energize at this time, however, since its winding is shunted by ground connected at the armature contacts of stepping relay 316 over conductor 354. When in response to the upward movement of the brush shaft of the incoming selector, the stepping relay 316 is shunted out in the well-known manner, the, ground connected to conductor 35 1 is removed and counting relay 3 energizes, transferring the ground connected to conductor 35 1 through its armature and front contact and thence through the armature and back contact of relay 2 and thence through the winding of relay 2 to battery and ground. In the well-known manner each counting relay in turn is energized untilrelay 0 attracts its armatures, whereupon'the fundamental circuit is broken pt the right-hand armature contacts of, re-

ay 0. i

Relay 0 also upon energizing closes a circuit for driving sequence switch 300 out of position 6 and into position 8, This circuit may be traced from grounded battery through the winding of sequence switch 300, the lower right-hand contact of office register cam 113 (9), the front contact and left-hand armature of relay 0, sequenceswitch cam 310 (6), and thence to ground through the left-hand contact of office register cam 415 (9).

With sequence switch 300 in position 8, the fundamental circuit is again established between the incoming selector switch and the stepping relay 316 of the sender over conductor 117, the right-hand armature and back con-tact of relay 315, the right-hand armature and back contact of relay 0, the winding of stepping relay 316, the upper left-hand contact of sequence switch cam 306 and thence over conductor 118. incoming group selection now takes place under the control of the thousands and hundreds registers. The energization of relay 316 now closes a circuit from ground at the armature of relay 316 through the upper contact of sequence switch cam 309 (8), the lower contact of oiiice register cam 1-16 (9), the lower contact of the thousands register cam 422 (6), the upper contact of the hundreds register cam 131 (9), conductor 355, armature and back contact of relay 1, the winding of relay 1, and thence to grounded cattery. Relay 1 energizes in this circuit and closes a locking circuit for itself extending through its .vinding through the winding of relay 1, the armature and front contact of relay 1, and thence to ground at the upper right-hand contact of sequence switch cam 303 (8 to 8-1:). Relay 1 does not energize at this time since its winding is shunted at the armature contacts of stepping relay 316. When, however, in the group selection mo ernentof the incoming selector shaft, an intermittent ground is connected to the fundamental circuit and the relay 316 becomes deenergized, the shunt is removed from around the wind ing of relay '1 and this relay energizes, transferring at its armature contacts the ground on conductor 355 to the winding of relay 0. Upon the next deenergization of stepping relay 316, relay 0 energizes, opening the fundamental circuit at its right-hand armature contacts and closing at its lefthand armature and front contact, a circuit for driving sequence switch 300 out of position 3 and/into position 10, this circuit extending as previously traced through sequence switch cam 308 and through office register cam 113 0 After the group selection movement of the incoming selector swi ch 200, this selector switch hunts for an idle trunk in the selected group extending to a final selector switch 201. When such an idle trunk has been found, the fundamental circuit previ ously traced through the winding of relay 316 is extended through the winding of the control relay (not shown) of the final selector switch 201. Final hundreds selection may now take place.

Upon the initial energization of stepping relay 316 over the fundamental circuit, a circuit is established from ground at the armature contacts of relay 316 through the upper right-hand contact of sequence switch cam 307 (10), the upper right-hand contact of the hundreds register cam 133 (9) over conductor 353, the armature contacts of counting relay 9, and thence through winding of counting relay 9 to grounded hattery. in the well-known manner counting relay 9 locks up through the winding of counting relay 9', the counting relay 9, however, remaining deenergized until the shuntaround its winding is removed by the deenergization of stepping relay 316, which takes place upon the upward movement of the final selector switch in its brush selecting movement. In the well-known manner counting relays 8 to 0 energize and when counting relay 0 energizes, the fundamental circuit is opened at the righthand armature contacts of this relay, and a circuit is closed at the left-hand armature contacts for driving sequence switch 300 out of position 10 and into position 12. Upon leaving position 10, the counting relays are un locked and the circuits of the sender prepared for tens selections.

With sequence switch 300 in position 12, the fundamental circuit is again established and relay 316 again energizes, closing a circuit extending from ground at its armature contacts through the lower right hand contact of sequence switch cam 307 (12), the lower left-hand contact 4 11 (8) of the tens register, conductor 357, the armature and hack contact of relay 7 and thence through the winding of relay 7 to grounded battery. Relay 7 in the welllrnown manner closes a locking circuit for itself extending through the winding of relay 7, relay 7, however, remaining deenergized until stepping relay 316 deenergizes, when the final selector shaft 201 encounters the first conducting segment of its commutator during the tens selection movement of its wiper shaft. V'Vhen relay 7 becomes energized, transferring the ground connection on conductor 357 to the winding of relay 6, counting relays 6' to 0 energize in the well-known manner, and when relay 0 energizes, the fundamental circuit is again opened at the right-hand armature contacts of this relay and circuit is closed at the left-hand contacts of this relay for driving sequence switch 300 out of position 12 and into position 14. Upon leaving position 12, the lockedup counting relays hecome deenergized to prepare the circuits of the sender I01 units selection.

Vi ith sequence switch 300 in position lei,

the fundamental circuit extending throughthe winding of relay 316 is again established and relay 316 energizes, closing a circuit extending from ground at its armature contacts through the lower left-hand contact of sequence switch cam 307 (1 1), the upper.

' v at the upper right-hand contact of sequence switch earn 308 (1 1 to 14%;.) Relay 5, however, does not energize in this circuit since its winding is shunted by ground on conductor 358. As soon as relay 316 becomes de: energized due to the intermittent grounding of the fundamental circuit during the units selection movement of the final selector switcl, the shunt around relay 5 is removed and this relay energizes transferring the ground connection on conductor 358 to the winding of counting relay 4. In the welllrnown manner counting relays 1 to Oenergize in succession, and when relay 0 energizes. the fundamental circuit is opened at its right-hand armaturecontacts, anda cir cuit is closed through its left-hand armature contacts for driving sequence switch 300 out of position 14 and into, position 16..

Upon leaving position 14-, the locked-up g relays are denergized. Upon reaching position 16 a circuit is closed excountin tending from ground at sequence switch cam- 311 through the, lower left-hand contact of sequence switch cam 102 (11'), and through themagnet winding of sequence switch 100 to grounded battery for driving sequence switch 100 out of position 11 and into the talking position, 16.- Upon leavingposition 11, the conductors 117 and 118 of the fundamental circuit are disconnected from the.

talking strands of the link circuit and the shaftwipcrs 134 and 135 are connectedover the upper contactsof sequence switch cams 110 and 111 to the right-hand windings of the repeating coils RC, and through the winding of the calling supervisory relay 130.

Qequence switch 100 also opens the holding circuit of relay 3140f the sender at sequence of the final selectorswitch 201, tern1inals of the called line B are tested in the well"- known manner, and if theline is found idle,

j ack j and plug I P through the windings of repeating coil C over the wipers of office selector switch 200' and thewipers of the final selector. switch 201. Following the application ofringing current to the line of the called subscriber" and the response of the,

called subscriber v supervisory relay 130 functions in the usual manner to give the operator a signal.

Upon the termination of the conversation, the subscriber srestore their receivers to the switch-hooks, thereby causing the operation of the answering supervisory rela r 131, and the calling supervisoryrelay 130 to indicate to the operator that the conversation is F111 ished and that she may take down the connection. In response to these signals, the operator withdraws the plug P "from jack J, causing thereby the deenergization of cut-off relay 10' and of relay 112. The deenergization ofcut-ofi relay lOrestores the.

connection ofthe subscribers line relay 18 through the winding, of sequence switch magnet10O through the upper right-hand contact .of'sequence switch caIn IOEZ (2 to 16) and thence' to' ground at the back contact and armature of relay 1 12. Sequence switch 100 thereupon moves into position 18 in which position circuit is established for the down-drive magnetf1 32'. to]; restoring the switch. shaft of the oiiiceselector 116. This circuit ay; be traced from grounded battery through thewinding of theydown-drive magnet 182 and thence, to ground through the upperright-hand contact of sequence switch calnfl0 5' ]Down-drive Imagnet 132.

upon energizing presses the depending portion oftheswitch shaft against the con-. stantly rotating down-drive roller. 133,

a talking connection iscut-thrbugh from the 03.11111 subscribers line over the contacts of selector switch, 116, wipers of the incoming thereby causing the restoration of the switch shaft to normal. When the switch shaft reaches normal," a. circuit, is established eX- tending from ground at brush 129 overnormal commutator segment 134C through the upper right hand contact of sequence switch cam 106, and thence through the magnet winding of sequence switch 100 to grounded battery for driving sequence switch .100 into normal position. i

The restoration of the incoming and final selector switches then proceeds in the wellknown manner.

Connection with cm oflioc equipped with stap by-szep switches.

If it be assumed that the calling subscribed desires a connection with subscriber C, whose line terminates in the office Y which is equipped with step-by-step switches, and that the designation of subscribers line C is 36975, the circuits function in the manner previously described up to the point where sequence switch 300 of the office sender is driven into position 4 and the fundamental circuit is established between the stepping relay 316 and relay 115 of the oifice selector switch, with the exception that the operator has depressed the #3 oflice key for directing the movement of the office selector to a group of trunks leading to the office Y.

The energization of stepping relay 316 over the fundamental circuit including the winding of relay 115, establishes a circuit extending from ground at the armature of relay 316 through the upper-left-hand contact of sequence switch cam 307 (4) through the lower left-hand contact of ofiice register cam 417 over conductor 354, armature and back contact of counting relay 3, the

. winding of counting relay 3, and thence to grounded battery. Counting relay 3 thereupon energizes closing a locking circuit for itself extending through the winding of relay 3. Relay 3, however, does not energize at this time since its winding is shunted by ground on conductor 354. As soon, however, as the brush 123 engages the first conducting segment of commutator 124, relay 316 deenergizes in the manner previously described, thereby removing ground from conductor 354. Relay 3 thereupon energizes, transferring ground on conductor 354 through its armature and front contact, and armature and back contact of relay 2 to the winding of relay 2. I

The counting relays 2 to 0 energize in succession in the manner previously described during the group selection movement of the office selector switch. When relay 0 energizes, the fundamental circuit is opened and a circuit is closed through its left-hand armature and front contact for driving sequence switch 300 out of position 4 and into position 6, this circuit extending from grounded battery through the winding of sequence switch 300 through sequence switch cam 312 (4), the front contact and left-hand armature of relay 0, and thence to ground at the upper lefthand contact of sequence switch cam 308 4). When sequence switch 300 leaves position 4, the loclrcd-up counting relays become deenergized, in position 6, since the office register has now been set to position 3 for selection of office Y, a circuit is now established for driving sequence switch 300 through position 6 and into position 8. This circuit may be traced from grounded battery through the winding cf sequence switch 300 through sequence switch cam 313 (6), and thence to ground at the upper right-hand contact of office register cam 415 The purpose of driving the sender sequence switch through position 6 is to eliminate one selec tive position which. is necessary for translation when a connection is established with an ofiice having switches of the power-driven panel type.

Upon the opening of the fundamental circuit when counting relay 0 energizes, following oihce selection, the sequence switch of the office selector was driven into position 6 and an idle trunk in the selected group was "selected in the manner previouslydescribed. Upon the selection of such idle trunk, the sequence switch 100 was driven into position 11, in which position conductors 117 and 118 of the fundamental circuit were connected over the talkin wipers 134 and 135 of the office selector to the trunk terminating in the first selector switch 250 of office Y.

A new fundamental circuit is now established extending from grounded battery through the right-hand winding of line relay 251 of selector switch 250, through the side switch wiper 252 and its first position contact, over trunk conductor 253, wiper 134 of the oiiice selector, sequence switch cam 110 (11) conductor 1.17, the right-hand armature and back contact of stepping relay 315, sequence switch contact 311 (6 to 18), register earn 418 (3), sequence switch cam 312 (6 to 18), winding of stepping relay 316, the upper right-hand contact of sequence switch cam 306, (55} to 14), conductor 319, the lower left-hand contact of ofice register cam 414 (3), conductor 318, conductor 118, sequence switch cam 111 (11), Wiper 135 of the office selector, trunk conductor 254, side-switch wiper and its first position contact, and thence through the left-hand winding of line relay 251 to ground. Line relay 251 and stepping relay 316 energize in this circuit, relay 251 preparing the stepping circuit of the first selector switch 250 for stepping the wiper shaft in its vertical selective movement.

Stepping relay 316 upon energizing closes a circuit extending from ground at its arma ture contacts, through the contact of sequence switch cam 309 (8), the upper contact of office register cam 416 the upper left-hand contact of thousands register cam 423 (6), conductor 356, the armature and back contact of counting relay 6, and thence through the winding of counting relay 6 to grounded battery. Counting relay 6 energizes in this circuit and establishes a locking circuit for itself through the winding of relay 6. vRelay 6, however, does not energize in this circuit since its winding is shunted by ground on conductor 356.

Since the office register has been positioned in position 3 for the selection of an ofice having step-by-step switches, a circuit is established for stepping relay 315 which may be traced from grounded battery gizes in this circuit and closes a locking circuit for itself extendin through the wind ing of relay 7 Relay however, does not energize at this time since its winding is shunted by ground on conductor 357. Upon the first opening of the fundamental circuit by stepping relay 315, the stepping relayl of the final connector switch and the stepping relay 316 of the sender deenergize, stepping relay 316 removing ground from conductor 357, thereby permitting the energization of counting relay 7.

Stepping relay 315 causes successive open- 'ingsof the fundamental circuit to cause the vertical stepping of the final selector switch and successive deenergizations of stepping relay 316 of the sender. Counting relays 6 to 0' thereupon energize in succession and remain locked up over sequence switch cam 308 (12 to 12%). Upon the energization of counting relay 0, the circuit of stepping relay 315 is opened at the left-hand armature and back contact of relay O to discontinue theinte'rmit'tent opening of the fundamental circuit, and a circuit previously traced is closed for energizing relay 320, which in turn after an interval closes a circuitfordriving sequence switch 300 out of position 12'anol into position 14. I

" Sequence switch 300 upon leaving position'12 opens the locking circuit of the locked-up counting relays, which thereupon deenergize, counting relay, 0 re-establishing the energizing circuit of stepping relay| 315. Immediately following the vertical stepping movement of the connector switch, the fundamental circuit through stepping relay 316 is again established, and with sequence switch 300 in position 14, a circuit is established from ground at the armature contacts of relay 316 through the lower left-hand contact of sequence switch cam 307 (14), the upper right-hand contact of the units register cam 451 (5), conductor 358, the armature and back contact of counting relay 5', and thence from the winding of counting relay 5 to grounded battery. Relay 5 energizes in this circuit and closes a locking circuit for itself extending through the winding of relay 5. Relay 5, however, does not energize at this time since its winding is :tesaeec shunted by ground on conductor 358. Upon the first opening of the fundamental circuit by stepping relay 315, the stepping relay of the'connector and stepping relay 316 of the sender deenergize. Relay 316 removes ground from conductor 358 permitting the energization of counting relay 5 which thereupon transfers ground from conductor 358 through its armature and front contact, the armature and back contact of relay 4; to the winding of counting relay 4.

Stepping relay 315 causes successive openings of the fundamental circuits to cause the rotary stepping movement of Com nector switch 257 and successive deenergizations of stepping relay 316, which in the manner previously described causes the successive energization of counting relays 5' to O.

Upon the energization of relay 0, the'circuit for stepping relay 315 is opened at the left-hand armature and back contact of relay 0, and a circuit is established for relay 320 for driving sequence switch 300 out of position 14 and into position 16. Sequence switch 300 upon leaving position 14 opens the locking circuit of the locked up counting relays. Upon moving into position '16 a circuit is closed over sequence switch cam 311 for driving sequence switch of the ofiice selector out of position 11 and into position 16. Upon leaving position 11 relay 314 is deenergized causing the movement of the sender sequence switch 300 out of position 16 and into normal position.

Upon the movement of sequence switch 100 of the oflice selector into position 16, the talking circuit is cut through from the calling subscribers line to the connector switch 257, and the testing of the terminals of the called line C and ringing up the called subscriber proceed in the well-known manner. The restoration of the connection following the termination of the conversation takes place in substantially the same manner as described in connection with the explanation of a connection to office X.

From the preceding description it will be apparent to those skilled in the artthat a sender fundamentally designed for use in controlling the settin of switches of the power-driven type has been employed in a very simple manner for controlling either switches of the power-driven type or switches of the step-by-step type, the alteration of the circuits of the sender for controlling switches of either type being dependent entirely upon the setting of the oflice registerv which controls the setting of the office selector switch to determine the particular oflice to which the connection is to be extended.

While the invention has been disclosed in connection with a system of the semi- Hit) automatic type in which the operator sets up the designation ofthe desiredli-ne upon her bank of keys, it is tohe understood that the invention might equallywell loe appliedto a system of the full automatic type in which "the registers are set directly by the callinoc subscriber throughthe manipulation .o thesending-dial associated with the sub-station apparatus Such a full automatic system is disclosed-in the patent to Polinkowsk-y, No. 1,193 053, issued Aue' gUS'Dl, 1916;. 7

What-is claimed is:

1. In a telephone exchange-system, aphiral-ity-of offices, aJplura-litvof-switches' arranged to be driven from continuously operatingsource-of kinetic energy in cer tain of said oflices, a plurality; of step-by step switches in other of I said ofiice's and a switchwcontrolling mechanism associated withi-eachof said certain offices compris ingmeans for registering 'linedesignations; means under the control ofsaidregisteringf meansfor selectively controlling the 1013,61- ation of saidcfirst mentioned switches to extend connectionsi withinn the: ofiice Wi th which it is associated or to= other offices,- and means for altering the cir cuits of said mechanism. whereby' said step bygstep switches arecont-rolled ibysaid mechanism loeen extended to" when connections have oflices -l12tV111g: step by-step switches QUIn-Ja telephone exchange system an originating office, a plurality of-distance to bedriven fromi-a-continuously operating source of kinetic energy for extending con nectionsto-any oneof said distant offices, a pluralityof swit'chesrin certain ofvsaid distant offices,- arranged tobe driven from a continuouslyoperatlng .source oi kinetlcenergy, aplurality of step-by ste'p}-sw1tch'es-- in otherofsaid distant offices, and'aswitch" controlling, mechanism! -1Il 831d originating; office compr smg means for reg steringhne designations, means under the control of'said registeringzmeans for selectively controlling the operation ofsaid switch in sai d originating oflice to exten'd a connection to anyone or said distant ofiices and for controlling ithe switches'of thedistant oflice if the connection is extende d'to an I office having switches arranged to be driven from a continuously operating; source of: kinetic energy and meansz for altering, the circuits of SELlCl' to be: driven: from acontinuously operating? sourcewof kinetic energy: for extending A connections: to: any, one of 82:16.? dist-ant: offices; 1 a

plurality of switches in'- certain of said distant offices arranged to be driven from a coi'itinueusly operatingsource of? kinetic energy, a plurality ofsteprby-stepswitches in other of said. distantkoffices a switch controllingmechanism in said oiriginating oflice,- an operators' v key-board for variably setting; said mechanism, means under the control ofsaid mechanismfor selectively controlling the operationof said switch in saidoriginating office to exte'nd a" connection to any one of said-distantoffices and for'controllingfithe switches of the dis tantofiice if the connection is extended-tot an; office having switches arranged to be driven front a continuously. operating source-of kineticenergy and means for altering thecircuits of said mechanism whereby, said step-by-step; switches are controlled by I saidmechanism when theconnection .is extended to an oflice having'step-by-step switches.-

4; In a telephone exchange system a plurality of offices,-v apluralitycff switches in'certain of said offices arranged toi be driven from acontinuously operating source of kineticenergy, a plurality of step-by-ste'p switches in other of said-oflices, asetofrg isters' associated with each of said: first H1811- tioned offi'ces, means for variablyzposi tioningsaid registers; means under the-control-of said registers for selectively controlling theoperation of said first-mentioned switches to extend connections within; the office- Withwhich said registers are associatedor to other ofiices and means for alteringwthecircuit-s of said second'means whereby. said; step-by step switches are controlledby said second 1 means when connections have been extended tooflices having steprbyrstepf switches. Y a

5. In atel-e'phone exchangesystem," a plurality of oflices; a plurality of? switches in certain ofsaid oflices arranged t'ot'be driven from a continuously ope-ratingisource of kinetic energy, a plurality of steploy-step: switchesin' other of said officesya set' 'of reg= ister associated with one 0f said--firstmentioned oflices, means forvariably positioning saidregisters, means under the control of:

said registers for selectively controlling; the operation of said-firstmentioned switches *to' extend connections within the" office"; with which said registers are associatedor toother oflices' and means for altering ithe 'cir cuit's of'said second means whereby-said step-by-step: switches are controlled by said second 'means when connections have been extended to said ofiic'es'having: step+bystep switch-es; v 6. In a telephone exchange system; a plurality of: ofiic'essa" pluralit'y'wofi switchcs' in certain otsaid offices arrangedto be driven 'from a continuously driven sourceofkinetic energy,aplurality of stepby-stepy switches in other of said offices, a set offre'gs-r 

